Process for the manufacture of synthetic liquid fuels



' May 7, 1929. E.'A. PRUDHOMME 1,711,856

Pnocmss Fon THE MANUFAGTURE oF SYNTHETIC LIQUID FUELS Filed April '7, 192s 'cATALYsf/Ps AasofaE/e @150A/:rbi F G H J K l/ ll 1 2 e L M I 'f' E a y s. E/ s I ffmc/,NG 6,45 COMMA/55 GFA/554 TOKS Paf/Nif@ QfP/f/f/wo/F A I I I -I I I I I f S" l@ -eaz rI J IE I I IV WWI cdfwmm l Patented May 7, 1929.

UNITED STATES PATENT oFEicE.

EUGN ALBERT PRUDHOINDVIE, OF NEUILLY-SUR-SEINE, FRANCE, ASSIGNOR T SO. i CIT INTERNATICNALE DES PROCEDES FRUDHOMME (S. I. 1. PJ, OF PARIS, FRANCE, A LIMITED JOINT-STOCK COMPANY 0F FRANCE.

PROCESS FOB THE MA'NUFAOTURE 0F SYNll-IIETIC LIQUID FUELS.

Application lcd Aprii 7, 19:46, Serial No. 100,464, and in France March 9, 1926.

` In my Vprevious application Serial No. 8,655 filed January 2Q, 1925, I have described a process and apparatus for the manufacture of synthetic liquid fuels, which 5 comprise a particular cycle of operations by This cycle of operations, which is carriedv through at normal pressure, comprises, distillation of the starting materials (lignites, peats, vtars or the like) in an apparatus wherein these materials suit-ably heated are traversed by a stream of hot gases or vapours (water gas, steam, residual gas from coking or the manufacture of lindustrial liquid-fuels). On leaving the gasification apparatus, the distillation gases, enriched with hydrocarbons by the addition of the added gases or va ours, are purified, with a view to initial e imination of deleterious substances, in particular sulphur, the purifying bodies being, for examplemcatalytic agents such as metals or metallic oxides (nickel or nickel oxide), and then led, thus purified, over a bank of catalyzers arranged in series. Such catalysis in cascade ensures the formation, in-consecutive steps, first of a very large proportion of methane (CH4), with little acetylenic compounds, then the transformation of such methane, by splitting up into acetylene (C2H2) and free hydrogen i/n the nascent condition, and finally this large quantity of acetylenic compounds being formed, their polymerization occurs in a final catalyzer and gives rise to carbides to which the free .h drogen attaches itself,

to eect their trans ormation into light hydrocarbons, condensible at a temperaturev varying between 180 and 220 C.

One of the essential characteristics of the above recited process is to be seen in the fact that vthroughout the entire operative cycle, from the issue of the gases fromjthe kiln, the entire mass of such gases (comprising then a mixture of products of distillation of the substances treated andy of residual or other additional gases, which 'served for their enrichment) until their issue from the last of the catalyzers in series, care is taken to maintain a temperature sufciently elethem anew.

vated to avoid any condensation, and lconsequently, any formation of tars.

This precaution which it is easy to observe, for example by disposing the whole of the purifiers and series of catalyzers in one and the same heated structure, connected to the distillation kilns or retorts, has not simply the' result of permitting a continuousl operation; by avoiding choking and incrustation by products of condensation; it provides above all another advantage consisting in integrally conserving the gaseous mixture, in order to treat same progressively bly the catalyzers in series; in particular t e starting solid or other combustible material are maintained, which especially promotes the enrichment of such product, during the course of the catalysis.

In the successive catalyzers, these condensible substances pursue their rle like noncondensible substances. In effect, in the first catalyzei' of the series, there is produced a general hydrogenation, a defoxidation of bodies easy to hydrogenate in the stateY wherein such bodies leave the purifiers; thus if the carbonmonoxide (CO) of the noncondensible products gives rise to the production of methane (CHQ at the same time, the condensible bodies such as the phenols (C0H5OI-I) lose their oxygen and pass in the state-of benzines (06H6). This preparatory stage is particularly necessary in order toensure a deoxidation, but the definite enrichment cannot be immediately effected. Likewise it is lconvenient to take up again the incondensible products and the condensible products in order to enrich To effect this, they pass into the second catalyzer, wherein occurs a splitting-up of the bodies which, such as methane (CIL) have just become saturated, or the saturated bodies of the same series pres- 'ent in the entrained tar yvapours (decane,

ondecane, dodecane, etc.), that is to say an opening of the chain which permits a new hydrogenation which will occur in lthe third catalyzer. The hydrogen nascent in the second catalyzer apparatus, does not proceed alone from thetransforination of the mcthane and the acetylene, but alsoy from the action which the remaining carbonmonpxide exercises upon the stream. In the third catalyzer of the series there is finally proheavyv hydrocarbons derived from the Y duced simultaneously with thel polymerization the saturation with hydro en of all the condensible and honcondensib e substances alyze-r element,'an initial hydrogenation tol the degree possible, by shbstitution of hydrogen for oxygen; this initial hydrogenation is followed, in" a secondvcatalyzer, by a breaking up ofthe initial saturated products, with a view toplacingsuch products in a form facilitating the fixationr of the nascent hydrogen which is produced at the same time with such breaking up. It only remains to bring the nascent hydrogen and the -bodies on which it is to become fixed, into the presenceof a third catalyzer agent which facilitates these reactions. l

The applicant has, moreover, indicated how, in the plantl itself which serves for the carrying out of .his process, contaminated catalyzers can be regenerated 1n the dry condition, Without it being necessaryV to discharge the tubes containing them,'th1s being leffected by the employment of streams of vapours of an organic acid, such as acetle` acid, fol-mie acid, lactic'acid, whichinef feet-ing the .removal of the sulphur in the form of Hg'S, give rise to acetatesformates or lactates from which the metal can then be recovered, in situ, by a simple elevation of temperature effecting decomposition of these salts. Y y l It is important to recall all thesercharacteristics 1n order better' to appreciate the interest and the importance of the improvements which form the subject of the present invention'.

The applicant has] recognizedffirst of (all,

that if it is convenient to retain the useful 'tween `thc apparatus producing.;l the (i0 condensible substances, such as the tar vapours, in the gaseous mass (to be submitted,

after passage through the purifiers, to the action of the catalyzers in series), for the reason that these substances singularly r0- mote the richness of the light'product W lich is obtained on issue from the said eatalyzer, it is on the other hand preferable toelimil nate those of these condensible products of high boiling point, which distil only at a temperature above 400 C. These very heavy substances-are, for this purpose, and according' to the present improvements, separated in a dephlegmator maintained at a temperature ofabout 400 C., "disposed beas (kiln, retort or "the like) and the batterygof purifiers which can contain metallic or oxypurifiers, disembarrassed of .the heavy sub- 1,v11,'sso, w

rocessl however, bthey retain, in compensation, all. the tar va ours which would condense be, low 400 the condensation in the puritiers and the catalyzers being then avoided by the maintenance by a sultable temperature in the whole of these apparatuses and intermediate pipes. This temperature to be maintained progressively decreases, not only because the mechanical entrainment of the condensible products avoids in part an 'stances which distil above 400 C. only' condensation, but above all because the ro ucts progressively become li'hter. onse'- quently, inthe plurifiers will be maintained' a temperature w ich will not exceed 350 C., and, in the catalyzers,a temperature which will generally not pass above 250 C.

The drawings4 indicate diag'rammaticallyv in Figs. 1 and 2' two plants for carryingV out the invention.

t0n leaving the dephlegmator B, as shown in the schematic view of the plant in Fig. 1 of the acc panyin drawing, the roducts pass through a puri er C constitute according to the invention which forms the subject of an application for patent filed April 7, 1926, Serial/No. 100,462, entitled Process and apparatus for the hot desulphurization' of gases derived from the distillation of the pyrogenation of solid liquid and other combustibles,-by Eugene Albert Prudhomme.

In order to facilitate the circulation of the gases, the same are sucked on issue from the purifier', by means 'of a suitableexhausting apparatus (fan ejector or the like) D which,`

like the remain er of the plant is maintained at; a suit-able vtemperature (about. 300 0.), and this apparatus drives the gases into the catalyzers. i

According to the present improvements, the plant comprises means for the introduction in variable proportions, as required, of

fresh hydrogenating ases (water gas or the like) before the entry mto the initial catalyzers, in' order to maintain a suiiicientl 'active reducing atmosphere, and as wel between thesuccessive catalyzers, for theproduction," in the desired quantity, of the nascent hydrogen. The gases derived from any source, which may be residual products. (semi-cokes or the like are admitted by pipes E, E1, E2, provide with cocks e, el, e2. Obviously the quantity of gas to be introduced will be determined by the analysis vof of thefnal product or by tests effected as reraired during the course of manufacture.

f he successive catalyzers of the series can becconstituted, as `has been indicated in a prior application for patent tiled Januar 20, 1925 Serial No. 3,655, b various .meta sl or metailic oxides, in the ree elements of the series. For example, nickel may be em# ployed in the first, a mixture ofi-nickel and,

vanadium in the second, and a' mixtare of On issue from the last of the three catalyzers F, G, I-I,v the lightened and enriched gases or vapours pass through a condenser I at the surrounding atmospheric temperature, where they abandon condensible vapours, the liquid condensed constituting the most important portion of the products of manufacture.

The noncondensed vapours are led, by J, into an absorption apparatus K containing for example activated carbon or solvent oil. The permanent gases issuing from' the apparatus are led, by L, into a gasometer M;

' they may, as is well known, be utilized either for being reintroduced into the kiln or other .distilling apparatus A, or for injection at E, E1, E2, or finally they may serve for heating the various elements of the pla-nt.

The diagram of Fig. 2 shows the application of the above described improvements to a plant which comprises a return of the residual gases by a pipe N, to the apparatus which produces gas by distillation or pyrogenation. The latter comprises, in such case, tvvo elements A and A1 of 4which one A1 is charged with coke derived from a preceding operation, and which is traversed by the residual gases arriving by N-O1, before the gases are passed by P into the element A charged wlth fresh material.

When the material in the element A is exhausted, this element finds itself charged with coke, during which the coke in A1 will have been evacuated for replacement by a fresh charge of material to be treated. The residual gases will then follow the path N-O-A--A1.

Claims:

1. In a process for the manufacture of synthetic fuels which consists-in Vaporizing hydrocarbon products and passing said vapor-ized products through a series of successive catalyzers to a condenser, said catalyzers effecting in successive steps a general hydrogenation, a splitting up of the hydrogenated products into unsaturated products, and a saturation and polymerization of said unsaturated products, the step of adding to said vaporized products before entry into each catal zer variably proportioned amounts of re ucing as.

2. A process for the manu acture of svnthetic fuels which consists in subjecting ydrocarbon products vaporized within 400 C. to the action of a succession of catalytic elements effecting in successive stages a gen- 4alyzer, and condensing the resultant product.

3. A rocess for the manufacture of synthetic uels which conslsts 1n vaporizing hydrocarbon products, passing said vaporized products through a dephlegmator maintained at 400 C. and through a purifying element maintained at 350 C., subjecting said products to the action of a plurality of catalyzers effecting in successive stages a general hydrogenatlon, a splitting up of the hydrogenated products into unsaturated hydrocarbons, and a saturation and polymerization of said unsaturated hydrocarbons, While maintaininfr a temperature of not more than 250 throughout said catalyzers, adding to said products a separate quantity of reducing gas in each catalyzer, and condensing the resultant product.

4. A process for the manufacture of synthetic fuel which consists in vaporizing hydrocarbon products, separating out the heavier fractions in a dephleglnator maintained at 400 C., passing the lighter fractions through a series of catalyzers effecting in successive stages a general hydrogenation, a splitting up of the hydrogenated products into unsaturated hydrocarbons, and a saturation and olymerization of said unsaturated hydrocar ons, and condensing the resultant products.

'5. A process for the manufacture of synthetic fuel which consists in vaporizing h drocarbon products, separating out t c heavier fractions in a dephlegmator maintained at 400 C., passing the lighter fractions through a series of catalyzers effecting in successive stages a general hydrogenation, a splitting up of the hydrogenated products into unsaturated hydrocarbons, and a saturation and polymerization of said unsaturated hydrocarbons While adding to said lighter fractions a separate quantity of reducing gas before each catlyzer, and condensing the resultant products.

In testimony whereof I have signed this specification.

EUGENE ALBERT PRUDHOMME. 

